


There Will Be Rain

by snasational



Series: Old Cherryberry stuff [1]
Category: Undertale (Video Game)
Genre: Cunnilingus, Explicit Sexual Content, Fluff, M/M, Vaginal Sex
Language: English
Status: Completed
Published: 2020-12-11
Updated: 2020-12-11
Packaged: 2021-03-11 01:15:13
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,396
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28006794
Author URL: https://archiveofourown.org/users/snasational/pseuds/snasational
Summary: Blue is probably the nicest person Red has ever met.
Relationships: CherryBerry, Sans/Sans (Undertale), kedgeup (mentioned)
Series: Old Cherryberry stuff [1]
Series URL: https://archiveofourown.org/series/2065209
Comments: 8
Kudos: 119





	There Will Be Rain

**Author's Note:**

> CherryBerry is the fucking best and there needs to be more fics for them. 
> 
> Blue in this fic is meant to be canon underswap, not fanon. So, sorry, no super childish and immature Blueberry will be seen here. Not that he isn't cute, but I definitely prefer the og underswap sans lol. 
> 
> Also I haven't written skeleton porn since the seventh grade so I'm a bit rusty. Many apologies.

Blue is probably the nicest person Red has ever met. And, even though they’re technically considered the same, Red knows for a fact that they’re anything but alike. Even in appearance, there is a stark difference between them. Blue is soft, smooth bone and happy smiles. And Red is cracked, damaged beyond repair and constants scowling even with a perpetual grin. 

Sometimes, looking at Classic feels like looking into a mirror but it’s never like that with Blue. He’s so bright, so uniquely himself that Red feels blinded by it. He so desperately wants to reach out and touch that brightness, but he knows that he can’t. Red does not touch things unless he is breaking them. To touch would corrupt, and for the first time in a long time Red wants to preserve the sunshine that makes up Blue’s soul. 

And most importantly, he wants Blue to remain happy. The other would never have that with him around. Red can accept that. In his world, happiness and love and compassion is a thing of the past. To wish for something like that would be a show of weakness, a death sentence in itself. So, denying himself this comes as no great loss. 

It doesn’t matter that his ribcage feels tight when around him. 

He must ignore it. There’s no other option. 

*

“You’ve been avoiding me.” Blue accuses. 

Red blinks up at him from where his skull was resting on top of Classic’s table. They're all still stuck in his world, so sometimes finding peace and quiet with Boss and Puff running around is difficult. 

“Huh?” He blinks groggily, head still foggy from his nap. 

Blue frowns, an expression Red didn’t know he was capable of, and crosses his arms. “I said you’ve been avoiding me. We used to talk like, all the time! And now you won’t even look at me. Did I do something to upset you?” 

Guilt lingers heavy in his soul. He hadn’t meant to be so obvious, but he should have known better. Blue isn’t dumb. Contrarily, he’s just about as smart as him and Classic combined. And where the two of them can’t decipher emotions too well, Blue knows how to pin point every single microexpression on a person’s face. 

Another thing that takes his breath away. Red turns his face into the palm of his hands. One of his rings dig uncomfortably into his cheekbone but he chooses to ignore it. “Nah, I just haven’t been...sociable.” 

Instead of putting him at ease, the lie only makes him more upset. “You hang out with Papy and Classic all the time.” In the corner of his eye, Red sees that another expression crosses Blue’s face. His cerulean eye lights wobble slightly. “Do..do you not want to be friends with me anymore? Did I annoy you too much? I know that I am not like you or Classic, but I had thought that-”

“Stop.” Red interrupts, rougher than he intended. He winces at his tone of voice, and then repeats himself softly. “Stop. That isn’t it.”

If it were anyone else, he would’ve scoffed at the word ‘friend’. He would’ve cursed at them, maybe tossed a few bones in their direction and tell them to fuck off. Classic certainly wouldn’t call him a friend, and neither would Stretch. But Blue...Blue is an exception that he’s more than willing to make. 

Fuck, he’s getting soft again. 

“Then what is it? What can I do to make you like me again?” 

_ There’s nothing you can do to make me like you because I think I love you.  _

“Nothing.” He says instead. “You did nothing wrong, Blue. I ain’t mad at you so you can stop standing there looking like a lost puppy.” 

Blue doesn’t look convinced. “Promise?”

Red doesn’t like promises. They’re a dangerous thing, and a broken one could mean death. Promises mean commitment. Promises mean pain. Nothing good ever comes from a promise. This is a lesson Blue should learn so that he never gets hurt like Red and his brother have. In fact, there are a lot of lessons Blue should learn for his safety. A soul as kind as his is only going to lead to pain and that’s the last thing he wants for him. 

“Yeah yeah, whatever.” 

Red is an idiot.

The smile he gets in response makes him feel less like an idiot and more like a lovestruck fool.

*

“I’m a shitty person.” He tells Blue. They’re seated in a booth at Grillby’s. Red had originally wanted to go by himself, but Blue insisted. Everyone knows by now that Red has problems telling him no. Even Boss sees it, but surprisingly his younger brother has nothing to say on the issue. 

“That a coin in the swear jar.” The other says instinctively before he stops sipping on his smoothie. He tilts his head at him. “No you’re not!” 

Red grins at him, but it’s empty. “Nah, angel, I’m pretty sure I am.” The nickname slips easily, an old habit of his from back when he was a different person. Soft and affectionate words that don’t really hold a meaning to him anymore, but he still uses them because they slip easy off the tongue. 

It’s not the first time he’s called Blue by a pet name. He’s done it to Classic, too. But regardless a light dusting of blue spreads across the other’s cheekbones. “W-well! I don’t think so! The Magnificent Sans thinks you’re wonderful!” 

I’ve killed people, he wants to tell him. I’ve dusted monsters quicker than you could blink. But the idea of Blue knowing...it scares him. Red doesn’t want Blue to idolize him, but he also doesn’t want Blue to think of him as something evil even if he is. 

“If you say so.” He picks at the fries on his plate, appetite gone. 

“I do! I think you’re great, Red. You’re funny, and you always listen to me talk, and you always try and actually solve my riddles, and you always find the time to hang out with me, and you always tell me the truth instead of coddling me like i’m some baby, and you have a really nice laugh and a pretty smile and you’re smarter than I could ever imagine being and I l-” He stutters, the flow of compliments breaking. “I like you a lot!” 

Red’s face burns from how hard he’s blushing. His jaw is slack, and it takes him a moment to find words. Blue’s face is flushed too and it makes his soul constrict. 

“Sheesh kid, you’re way too nice to me.” I’m only going to end up hurting you goes left unsaid. 

  
“You deserve niceness! Edgy Papy is way too mean to you.”

“It’s his love language.” Red defends his brother easily. “At least mine doesn’t treat me like a kid.”

Blue doesn’t look upset at the insult. “That’s his love language.”

Red barks out surprised laughter at the sass coming from Blue. It’s hilarious because it’s unexpected. He would have thought Classic had come up with that retort. “Okay, touche. You got me fuckin’ beat.”

“Another coin in the jar.”

Between him, Boss, and Stretch, Red reckons Blue is going to come out of this whole multidimensional ordeal rich. 

*

“So,” Classic says one day. They’re sitting on the balcony, a quiet reprieve from the chaos that’s going on in the kitchen right now. He twirls a boney finger over the rim of his ketchup bottle, an amused expression on his face. “You and Blue?” 

Red chokes on his mustard and then scowls. “Fuck off.” 

Classic hums. “Stretch is pretending not to see it.” 

“Just like how I’m pretending not to see you and Boss.” 

This doesn’t draw much of a reaction out of Classic. The nonchalance of this guy is off putting at best, but Red can’t judge coping mechanisms. Where he’s angry, Classic is numb. He can respect that. 

“Got me there.” 

They sit in silence for a few more minutes. “I...he’s too good for me.” He confesses after a while. 

“Why?”

“He’s…” Red doesn’t know how to word it. “Everything I’m not. I’d only drag him down in the end.” 

“Heh. I think he’d disagree.” 

Red gives Classic a hard stare. “What’re you implying, sweetheart?” 

He takes a sip of his ketchup before answering. “What do you think I’m implying, buddy?” 

Before he can respond, they’re being called down for dinner. Red gives his doppleganger one of his best glares before stomping downstairs with the grace of an angry child.

*

“What has a thumb and four fingers, but it’s not a hand?” 

Red scrunches up snow between his phalanges, enjoying the feeling of the cold on his bone. It snowed harder than normal today and so Blue dragged him outside. At first Red watched Blue make a snowman, and then he instigated a snowball fight with MK, who is weirdly talented at making snowballs with his snout. 

It ends with them sitting underneath a pine tree at the edge of Snowdin. 

“Uhhh.” This one has him stumped. “A...paw?” 

Blue giggles. “No! Do you want me to give you the answer?” 

Red nods. 

“A glove!” 

He snorts. “Okay, that one was clever. Woulda never guessed it. You sure do know a ton of these, don’t you?” 

“Yeah! Riddles are fun. There’s always a correct answer, kinda like math. I’m good at that, too. Or, I think I am, but! The Magnificent Sans much rather prefers Riddles over numbers.” 

“Pfft. You know what I’m good at?” 

“What?”

“Sleeping.”

“Red! Don’t be so lazy!” He chides, but it has no heat. 

Red chuckles and they lull into a comfortable silence. The snow drifts down slowly, and watching it is almost enough to lull him into sleep. He feels at peace right now, with Blue by his side and the snow chilling him. 

“...Hey, angel?”

“Yeah?” 

“Why did carbon marry hydrogen?” 

If Blue had a nose, he’s sure it’d be scrunched up with how hard he’s thinking. Eventually, he gives up. “I am at a loss, for once! Why?”

“They ‘bonded’ well from the moment they met.” 

He’s afraid the joke will fall flat, but luckily Blue has some knowledge on chemistry. The pun draws out loud, genuine laughter. 

“Oh my stars! I should’ve guessed that one!” He says between guffaws. “Okay, okay, my turn! What do relationships have in common with Algebra?” 

Red has to bite back a grin. “I dunno, what?” 

“Haven’t you ever had an X and wondered Y?” 

This time, it’s Red laughing. “Hah! Good one!” 

They go back and forth for at least an hour, shooting puns and riddles and dumb jokes until Puff stumbles upon the two on his daily patrol. It’s the happiest Red has been since before he can remember. 

*

Eventually, Boss does end up saying something. Red is surprised at how long it’s taken him to do so. Usually his brother is quick to point out any and all flaws that he may have but for some reason Boss has very little negative things to say these days. They’ve been in Classic’s world for at least six months now and it’s definitely improved both of their moods. 

“Of course you’d fall for one of the happier ones.”

Red rolls over in their shared bed and flicks him between his eye sockets. “Don’t be an ass.” 

Boss swats his hand away. “I’m just saying!”

“Yeah? And I never thought you’d fall for one of the lazy ones.”

He sniffs, indignant. “I like his jokes.”

“We make the same jokes. So does Stretch, actually.”

“He has better delivery! The Great Papyrus can appreciate humor when executed properly.” 

Red rolls his eye sockets. “Keep telling yourself that.” He snuggles deeper into the comforter, exhaustion weighing his bones down unpleasantly.

“You know, Sans, I...don’t think I want to go back.” 

Red closes his eyes. “Same here bro.”

*

Waterfall here is beautiful. Instead of feeling sinister, it feels...calm. Walking through the echo flowers doesn’t bring forth sadness for the cries of monsters murdered next to them, and that in itself is a relief. Blue has tagged along yet again, but instead of chattering off like he normally does the other is silent. 

Almost like he’s contemplating something. 

Red finds a patch of grass that seems dry enough to sit on and plops down on his tailbone. Blue sits next to him wordlessly, still deep in thought. It makes him look like Classic, almost. Red lets him think, feeling no need to interrupt the comfortable silence that’s made a bubble around them. 

“Have you ever dated someone before?” Blue asks, suddenly.

Red pauses and takes a moment to think. “Uh...people don’t really date where I’m from.”

He looks saddened by this revelation. Red doesn’t think much of it. Back home they fuck and move on to the next monster. The only married couples are the ones who were together before things began to change for the worst. Fucking was a common thing, primal and fast and fun. An escape from the anger that awaits outside of closed doors. 

Before Blue, Red had never considered love a possibility. 

“Oh.”

“Aw, cheer up angel.” He can’t stop himself from patting the top of Blue’s skull. “It’s just how things are. Why do you ask, anyways?”

“...Just curious. Um,  _ would  _ you date someone?” 

Yes. You. He takes his hand back and sticks it in his pocket.

“I guess.”

Red turns to look at Blue and finds that the other has been staring at him. There’s an air of nervousness about him, which in turn makes Red nervous as well. Blue is acting...strange. He draws a blank as to why he’s acting the way he is. 

“Red, I have something to tell you.” He looks deeply into Red’s eye sockets, and with a sinking feeling Red knows where this conversation might lead. It makes sense now, the weird questions and the anxiety. How long have you felt the same way, he wonders. And do you know how much it’s going to destroy you?

“I lo-”

“You can’t.”

Blue frowns. “You didn’t even let me finish!”

Red shakes his head. “Blue, god.  _ Blue.  _ You don’t fucking understand what a bad decision falling for a guy like me is.”

Instead of hurt, like Red expected, Blue looks annoyed. “We’ve already had this conversation! Stop trying to say that you’re a bad person!”

“God fucking- I’m scum, angel, I ain’t nothing you need to be involving yourself with like that.” 

“Stop it! Stop saying bad things about yourself! You’re  _ not  _ some evil irredeemable person and I’m sick and tired of the way you degrade yourself! Don’t you know how amazing you are? You’re my friend. My first friend, my entire world. I can’t imagine a life without you in it anymore, and even if...even if you  _ don’t  _ feel the same way I’d never want you to think negatively like that.” 

It hurts. It hurts so bad, knowing Blue wholeheartedly believes in a lie. “But I am evil!” He raises his voice unintentionally. “I’m fucking trash! I’ve  _ killed  _ people. Dusted them, tortured them, hurt them. I did all of that because it’s my job too. Because it’s my  _ purpose.”  _

“You think I didn’t know that?” Red freezes. He wants to run away, but Blue moves to hold onto the sleeve of his jacket. “I can see LV, too, you know. Papy doesn’t know that I can, and I guess you didn’t either. I’ve known from the very beginning what level you were at, and despite that I still love you! What you did was out of necessity. I’m...I’m not saying it’s a good thing, what you did, but...but I understand. And it doesn’t make you a bad person!” 

Incredulity. Agony. Hope. Relief. It all flashes through him. Blue knows, and he doesn’t hate him. “You can’t be serious.” He says with disbelief. 

“But I am.”

And then he kisses him. Teeth to teeth, a spark of magic tingles where they connect. Red doesn’t pull away. By this point, he’s too weak to resist Blue for any longer. Now that everything has been laid out on the table, he finds that there’s no other reason to deny Blue what he wants. Still…he breaks away from the kiss and rests his forehead on Blue’s.

“You’re going to get hurt, you know.” 

Cerulean lights twinkle. 

“Then let me.”

They kiss again.

And again. 

_ And again.  _

It’s like heaven on earth, the way Blue magic intertwines with his own during their kisses. Eventually, Red shucks off his jacket and lays it on the ground. Blue gets the hint and allows Red to position them to where Blue is on top of the jacket and Red hovers over him, his hands caging Blue’s skull. Heaviness settles between them, tension so thick you could cut it with a butter knife. 

“Do you know how to make a tongue?” 

Blue flushes and nods. His right socket brightens, wisps of energy flowing from the eyelight before a small tongue lulls out of his mouth. The sight of it alone nearly makes him cum in his pants. Red finally bends down and takes his tongue into his mouth, humming contently at the pleasant buzz the physical magic brings. 

Blue whines softly, and with enough coaxing from Red, he copies the twirling motions the other makes. Blue’s hands slide from gripping his shoulders to sliding around his neck and cupping his cheekbone, urging Red to be as close as physically possible. 

After a few minutes of kissing, Red decides he wants to taste something new. He pulls back, taking in the way red spit dribbles from the corners of Blue’s mouth and the way his face is slack with lust. 

“Fuck, you’re so hot.” Red groans before tugging at Blue’s scarf. Blue lets him, and when it comes undone he tosses it to the side and leans down to lick a stripe down the vertebrae of his neck. His tongue catches on the groove of bone, and he laps at the creases that make up each section of his neck. 

“ _ Oh.”  _ Blue whimpers.  _ “ _ Oh, that feels nice.” 

And it tastes even better, Red thinks with a lecherous grin. One of his hands moves from beside Blue to tug at the collar of his shirt. “Hey, do you like this shirt?”

“What d- _ Red!”  _ He screeches when Red literally rips down the middle of it. Smooth bone is exposed to him, and the sight of a familiar but different ribcage greets him. His tongue gets even wetter, drooling down the side of Blue’s face. “I cannot believe you right now!”

“I’ll buy you another one.” Red says unapologetically. Without further ado, he dips his head down further and kisses Blue’s sternum. This certainly gets the other to shut up with a sharp gasp. He lavishes his ribs with attention, kissing and licking and stroking until Blue is nothing but a trembling mess beneath him. He begins to squirm even harder than before when Red curls his tongue around a floating rib. 

“Just look at you.” Red cooes. “I bet I could get you to cum from just this. Would you do that for me? Would you be a good boy and cum without me even touching that pretty little cunt of yours?” 

“Oh my god Red, that’s so  _ vulgar.”  _ Blue squeaks. Despite his disapproving words, Blue loops his femurs around Red’s hip bones and pushes his pelvis against the other. 

“Ngh-!” His pants feel wet, meaning Blue has already summoned his pussy. “Okay, I get it, another time. I’m gonna make you feel so good, angel. I promise.” He clacks his teeth against Blue’s cheek, who’s begun to whine again. 

Red shifts back down, even further than before, and places his hands at Blue’s waistband. When he gets no objection, he pulls them down and is met with the pleasant glow of his lover’s magic. Blue helps him out a bit, wriggling until the pants are pulled off over his boots and tossed away with his scarf. 

Like a good boy, Blue spreads his legs and presents Red with the sight of his pussy. It’s, for a lack of better words,  _ cute.  _ And puffy. The lips hide his entrance, and his clit peeks out at the top. A teasing sight, one that makes him thirsty. “God, fuck,  _ shit,  _ i’m going to fucking eat you alive.”

He drops his skull between Blue’s femurs and sets right to work. Red starts at the bottom of his formed cunt and laps all the way up until his tongue us twirling around Blue’s clit. The noises he’s rewarded with are fantastic. Soft mewls and yelps, sounds that will forever be stuck in his head now that he’s gotten to hear them. 

He uses his thumbs to spread apart his pussy. Blue’s entrance is clenching and unclenching, empty and begging for something to fill it up. Red is more than happy to oblige. He presses his face right against his cunt, the ridge of his nasal bone grinding against his clit as he begins to happily lap at the twitching entrance laid before him. 

“Oh, oh,  _ oh.”  _ Blue chants, his femurs trembling. Pressure at the back of Red’s head pushes him even harder against Blue. “Yes, just like that, please don’t stop Red. It feels so good, I need more, more-  **_yes!”_ **

Blue throws his head back when his tongue finally breaches his sopping entrance. The taste of it is amazing and indescribable. He pushes his tongue as deep as it will go, drinking from Blue’s cunt. Blue has completely taken the reins now, rolling his pelvis against his face and holding his skull down. 

Being dominated by Blue is a euphoric feeling, one he definitely needs to revisit later. 

“Red, Red I’m going to- something is- I feel like I’m going to explode!” 

Red hums in response, and suddenly Blue goes completely still, his jaw open in a soundless scream. Wetness floods from his pussy, coating Red’s face and tongue in his essence. Red catches as much of it as he can in his mouth, desperate to taste as much as possible. Blue bucks his hips a few times, and then slumps down onto Red’s jacket. 

Red leans completely back, wiping his ulna and radius across his face. He observes his work and feels immense pride. But, there’s a more pressing issue here, and said issue is currently pulsing in his shorts. He tugs the band down just enough to free his straining erection, and he sighs happily when the air hits the leaking member. 

He drags his hand up and down the appendage at a leisurely pace, giving Blue as much time as he needs to calm down from his first climax. His pre leaks out like a broken faucet, dripping down his hands and making a mess everywhere. “If you’re up to it, I can give you something even better than my tongue.”

Blue opens his eyes and blinks blearily at him before eyelights rest on the sight of Red pleasuring himself. Another wave of fluid gushes out of Blue’s pussy. “Yes, please. Give it to me.” 

Red chuckles. “Say no more.” He shuffles close again and presses the tip of his cock to his entrance. Slowly, he pushes forward. Just the tip in and the tightness is near unbearable. Blue keens, seemingly split between pain and pleasure. But Red keeps going, pushing and pushing until his pelvis is flush against the other’s.

“God, you feel so perfect around me.” He groans. 

“You’re big.” Blue’s voice is trembling, and Red realizes that he’s crying. Guilt slams into him, but before he can push out, femurs wrap around him and pull him closer. “It’s okay, I’m okay. The Magnificent Sans has never been bothered by pain.”

Red huffs at the response, but takes it anyways. He curves his spine until he’s got Blue caged between his arms, like he did earlier when they were making out. “I’m going to move now, kay?” 

Blue nods. 

At first, the pace is slow. A simple roll of the hips, just enough for Blue to acclimate to his cock quicker. But, well, Red has never been known for his patience before. Soon he’s pulling all the way out and slamming back in, punching breathless gasps from Blue. The slide is easy because of how soaked Blue is, and it makes the thrusting pick up at a breakneck speed. 

There’s nothing but the sound of wet magic and erotic noises filling the air. If anyone were to choose to take a stroll in this direction they would certainly be met with quite the sight. The thought of it fills Red up with possessiveness. If someone saw, then they would know that Blue is  _ his.  _ His to love, his to hold, his to pleasure. Let the whole underground see, he doesn’t care. 

“Ngh, it’s happening again, Red! Red, Red, Red, oh stars, I love you so much, I can feel it. It’s- It’s-!” Blue arches his back and clamps down,  _ hard.  _ His pussy spasms with the force of his orgasm and it’s enough to drive Red absolutely insane. He rails his pussy with abandon, chasing his own release by riding on the tailcoats of Blue’s. 

He cums hard, filling Blue up with his seed. His dick keeps throbbing, twitching over and over with so much cum. Red didn’t even know it was possible to cum this much, but the grip of Blue’s cunt milks every last drop out of him. A few more shallow thrusts, and he collapses on top of Blue. 

“Fuck. I love you.” 

“I love you too.” Blue murmurs, sleepily. 

They both pass out moments later, holding each other tightly. 

*

“9G.” Blue says, hours later. He’s wearing Red’s jacket, which is zipped up due to the fact that he no longer has a shirt. They’re still curled up, but soon they’ll have to go home. Stretch is bound to go crazy if his brother disappears for over half a day, and Boss wouldn’t be pleased if he disappeared either. 

“What?” 

“You have to put 9G in the swear jar.” 

Red snorts and pecks him on the teeth, deeply amused that Blue managed to keep count of all his curse words. “Anything for you, angel.” 

**Author's Note:**

> twitter is askeletonthot 
> 
> Kudos and Comments are always appreciated!


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